1. Field of the Invention
This invention relates to a driverless guided vehicle movable along a sensible guide path on a floor.
2. Prior Art
Generally, in order that all the wheels of a guided vehicle can be positively held in contact with a floor during the travelling of the guided vehicle, at least one of the wheels are mounted on a vehicle body through a spring. Conventionally, a detecting means, such as a detector for detecting the guide path or route and a detector for detecting sensible markings along the guide path, has been mounted on a vehicle body. FIG. 1 shows one conventional guided vehicle 1 which comprises a pair of drive wheels 2 disposed centrally of a body 3 and a pair of free wheels 4, 4 in the form of a caster disposed at the front and rear ends of the body 3, respectively. A detecting means 5 is attached to a lower portion of the front end face of the body 3. The two free wheels 4, 4 are mounted on the body 3 through respective spring means so that the drive wheels 2 can be positively held in contact with a floor 6 during the travelling of the guided vehicle 1 and that the guided vehicle 1 can be moved in a stable manner in forward and rearward directions along the guide path. With this construction, the body 3 is angularly moved or swung vertically about the drive wheels 2 during the travelling of the guided vehicle 1 under the influence of the spring means. As a result, the detecting means 5 is moved toward and away from the guide path and the sensible markings on the floor so that the sensitivity of the detecting means is adversely affected. Therefore, the operation of the guided vehicle 1 can not properly be controlled.